Step 1:
The first step to converting 398898991.5539 to a fraction is to re-write 398898991.5539 in the form p/q where p and q are both positive integers. To start with, 398898991.5539 can be written as simply 398898991.5539/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 398898991.5539, which in this case is 4. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 398898991.5539/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 398898991.5539/1 each by 10000:
Step 3:
Now the last step is to simplify the fraction (if possible) by finding similar factors and cancelling them out, which leads to the following answer for 398898991.5539 as a fraction:
398898991/1 / 1